Fuel tank capacity Monaco Cayman 2003 Diesel

CA Traveler wrote:
The Centroids I've had are very accurate, repeatable and stable. The design is 2 concentric tubes and when the fuel reaches the bottom of the tube that is E on the gauge. The tube length is cut to length so that the gauge reads E when there is about 20% of fuel remaining in the tank.

I'll respectfully disagree. I'm not just repeating what I heard. I owned a Monaco Diplomat for 9 years and had to adjust the gauge twice. The Centroid may be an accurate gauge when used in a fuel tank that is not mounted in a vehicle, but when it's mounted in a motor home and especially a large side to side tank like Monaco used, it's far from accurate.

I adjusted mine and many others. They are easy to adjust from the driver's side fuel door panel, once you clean the undercoating overspray off.

To adjust, you need to note where the needle rests in different situations. I estimated about 80-85 gallons in my 100 gallon tank were useable. I wanted 40 gallons to be my half a tank mark. I noted where the needle was when I took 40 gallons of fuel. I also noted where my gauge was when it was full.

When you adjust the sending unit, turn on the ignition and give the needle at least 20 seconds to come to rest after each adjustment.

I eventually got mine to show a half tank when I reached about 40-45 gallons. With that said, the unit still jumped around to different positions at various times, but would more often come back to the same spot.

Lastly.....there are thousands of Monaco owners with the Centroid gauge that will tell you they are FAR from accurate or consistent.

My new coach (Freightliner) has a more compact 100 gallon tank that is longer front to back than side to side. It's mounted just behind the front axle between the frame and is FAR more accurate than the Monaco/Centroid unit ever was.

Kidoo wrote:
I did not know there was a low fuel light in these, it did not light up yet. I wonder how much fuel is left normaly when the light comes on. I saw a panel on top of the pass through over the tank.

I just want to make sure I do not panic when the light comes on. When I go south, I normally wait until I get to a cheaper place to fuel up.

There are 2 adjustment screws on the sending unit. 1 for the main fuel gauge level and the 2nd for the low fuel light level. Doug

I did not know there was a low fuel light in these, it did not light up yet. I wonder how much fuel is left normaly when the light comes on. I saw a panel on top of the pass through over the tank.

I just want to make sure I do not panic when the light comes on. When I go south, I normally wait until I get to a cheaper place to fuel up.

DSDP Don wrote:
Monaco uses a large side to side tank and a Centroid fuel gauge. Because of the design of the tank and the fact that the Centroids are not very accurate, your fuel gauge will be way off. The Centroid fuel gauge sending unit is adjustable, but takes some work to get it relatively accurate.

Monaco uses a shallow side to side tank and of course diesel sloshes in this type of design. Diesel engines stop immediately when then get air so you don't want to run the tank low on fuel. For this reason Monaco sets the gauge to read E when the tank is about 20% full. The generator pickup and low fuel light are above that point.

The Centroids I've had are very accurate, repeatable and stable. The design is 2 concentric tubes and when the fuel reaches the bottom of the tube that is E on the gauge. The tube length is cut to length so that the gauge reads E when there is about 20% of fuel remaining in the tank.

The Centroid can be calibrated. Fill the tank then pull the gauge out and set empty. At that point you can measure it's length and measure the tank to determine how much fuel is left when the gauge reads E. Reinsert the gauge and adjust for F. I did this at a truck stop and my 04 Endeavor Centroid was cut to read E with 18% fuel left in the tank.

Best to add fuel before the low fuel light comes on as the generator pickup will be above the fuel level.

The fuel sender on Roadmaster chassis can be calibrated by set pot screws on top of the sending unit. Roadmaster chassis have access to the top of the Diesel fuel tanks unlike Frtline and Spartan. You fill the tank up and then adjust the set screw in small increments until the gauge needle is on the full line. It can take up to 30 minutes to do this as the gauge needle takes time to respond when adjusting the set screw. Doug

Monaco uses a large side to side tank and a Centroid fuel gauge. Because of the design of the tank and the fact that the Centroids are not very accurate, your fuel gauge will be way off. The Centroid fuel gauge sending unit is adjustable, but takes some work to get it relatively accurate.

I wouldn't call it unusable I would call it a reserve. You can use it in an emergency or if you feel lucky. In my younger days I would use the whole tank. This works out till you hit that situation where you coast off the hiway on fumes and find they are out of diesel. Had another place that was having power problems and the pumps wouldn't work. I start looking at 1/2 tank.
Bill

jwmII wrote:
Monaco in the past has recommended not taking the coach fuel level below 25%. This was found in their owners manuals. Sounds good to me. I usually start looking to refuel at half a tank. Never let it go to 1/4 or 25%.

Probably because it is a rectangular flat tank, it depends on how the fuel pick up tube is place and if there is more than one pickup, especially when fuel gets displaced going on long down or uphill.

25% would be like very close to empty line, like I was, this is too bad to carry that much or unusable fuel.

You don't want to go below 1/4 if you have a generator that is supplied from your fuel tank. A safety feature will keep the generator from running below that point to make sure you don't run out of fuel. We have never filled our Monaco from empty to full, so don't know. Ours is supposed to be a 75 gallon tank also (gas) and we start looking for a gas stop when we have between 1/4 and 1/2 tank.

Monaco in the past has recommended not taking the coach fuel level below 25%. This was found in their owners manuals. Sounds good to me. I usually start looking to refuel at half a tank. Never let it go to 1/4 or 25%.